| 摘要 |
PROBLEM TO BE SOLVED: To increase a coil space while restricting a reduction in magnetic performance.SOLUTION: Shapes of an inner peripheral surface 111 of an outer cylindrical part 11 of a rotor 10 and an outer peripheral surface 121 of an inner cylindrical part 12 of the rotor 10 are set to have a stepped shape satisfying a relation of D11<D12. Similarly, shapes of an outer peripheral surface 311 of an outer cylindrical part 31 of a stator 30 and an inner peripheral surface 321 of an inner cylindrical part 32 of the stator 30 are set to have a stepped shape satisfying a relation of D21<D22. With this arrangement as above, employing a relation that a thickness of a couter-armature side is thicker than a thickness of an armature side in regard to a thickness of each of the outer cylindrical part 31 and the inner cylindrical part 32 of the stator 30 in order to restrict a reduction of magnetic performance shows that it is possible to approach the second clearance D32 at the position of the counter-armature side towards the first clearance D31 at the position of the armature side in regard to the clearance between the outer cylindrical part 31 and the inner cylindrical part 32 of the stator 30 and thus it is possible to increase a coil space.SELECTED DRAWING: Figure 2 |
